| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___TYPE_TRAITS_ALIGNED_STORAGE_H |
| #define _LIBCPP___TYPE_TRAITS_ALIGNED_STORAGE_H |
| |
| #include <__config> |
| #include <__type_traits/conditional.h> |
| #include <__type_traits/integral_constant.h> |
| #include <__type_traits/nat.h> |
| #include <__type_traits/type_list.h> |
| #include <cstddef> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _Tp> |
| struct __align_type |
| { |
| static const size_t value = _LIBCPP_PREFERRED_ALIGNOF(_Tp); |
| typedef _Tp type; |
| }; |
| |
| struct __struct_double {long double __lx;}; |
| struct __struct_double4 {double __lx[4];}; |
| |
| typedef |
| __type_list<__align_type<unsigned char>, |
| __type_list<__align_type<unsigned short>, |
| __type_list<__align_type<unsigned int>, |
| __type_list<__align_type<unsigned long>, |
| __type_list<__align_type<unsigned long long>, |
| __type_list<__align_type<double>, |
| __type_list<__align_type<long double>, |
| __type_list<__align_type<__struct_double>, |
| __type_list<__align_type<__struct_double4>, |
| __type_list<__align_type<int*>, |
| __nat |
| > > > > > > > > > > __all_types; |
| |
| template <size_t _Align> |
| struct _ALIGNAS(_Align) __fallback_overaligned {}; |
| |
| template <class _TL, size_t _Align> struct __find_pod; |
| |
| template <class _Hp, size_t _Align> |
| struct __find_pod<__type_list<_Hp, __nat>, _Align> |
| { |
| typedef __conditional_t<_Align == _Hp::value, typename _Hp::type, __fallback_overaligned<_Align> > type; |
| }; |
| |
| template <class _Hp, class _Tp, size_t _Align> |
| struct __find_pod<__type_list<_Hp, _Tp>, _Align> |
| { |
| typedef __conditional_t<_Align == _Hp::value, typename _Hp::type, typename __find_pod<_Tp, _Align>::type> type; |
| }; |
| |
| template <class _TL, size_t _Len> struct __find_max_align; |
| |
| template <class _Hp, size_t _Len> |
| struct __find_max_align<__type_list<_Hp, __nat>, _Len> : public integral_constant<size_t, _Hp::value> {}; |
| |
| template <size_t _Len, size_t _A1, size_t _A2> |
| struct __select_align |
| { |
| private: |
| static const size_t __min = _A2 < _A1 ? _A2 : _A1; |
| static const size_t __max = _A1 < _A2 ? _A2 : _A1; |
| public: |
| static const size_t value = _Len < __max ? __min : __max; |
| }; |
| |
| template <class _Hp, class _Tp, size_t _Len> |
| struct __find_max_align<__type_list<_Hp, _Tp>, _Len> |
| : public integral_constant<size_t, __select_align<_Len, _Hp::value, __find_max_align<_Tp, _Len>::value>::value> {}; |
| |
| template <size_t _Len, size_t _Align = __find_max_align<__all_types, _Len>::value> |
| struct _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_TEMPLATE_VIS aligned_storage |
| { |
| typedef typename __find_pod<__all_types, _Align>::type _Aligner; |
| union type |
| { |
| _Aligner __align; |
| unsigned char __data[(_Len + _Align - 1)/_Align * _Align]; |
| }; |
| }; |
| |
| #if _LIBCPP_STD_VER > 11 |
| |
| _LIBCPP_SUPPRESS_DEPRECATED_PUSH |
| template <size_t _Len, size_t _Align = __find_max_align<__all_types, _Len>::value> |
| using aligned_storage_t _LIBCPP_DEPRECATED_IN_CXX23 = typename aligned_storage<_Len, _Align>::type; |
| _LIBCPP_SUPPRESS_DEPRECATED_POP |
| |
| #endif |
| |
| #define _CREATE_ALIGNED_STORAGE_SPECIALIZATION(n) \ |
| template <size_t _Len>\ |
| struct _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_TEMPLATE_VIS aligned_storage<_Len, n>\ |
| {\ |
| struct _ALIGNAS(n) type\ |
| {\ |
| unsigned char __lx[(_Len + n - 1)/n * n];\ |
| };\ |
| } |
| |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x1); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x2); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x4); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x8); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x10); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x20); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x40); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x80); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x100); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x200); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x400); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x800); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x1000); |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x2000); |
| // PE/COFF does not support alignment beyond 8192 (=0x2000) |
| #if !defined(_LIBCPP_OBJECT_FORMAT_COFF) |
| _CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x4000); |
| #endif // !defined(_LIBCPP_OBJECT_FORMAT_COFF) |
| |
| #undef _CREATE_ALIGNED_STORAGE_SPECIALIZATION |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___TYPE_TRAITS_ALIGNED_STORAGE_H |